Gas burning appliance for absorption refrigerators



y 1933. L. s. CHADWICK -r AL 1,917,751

GAS BURNING APPLIANCE FOR ABSORPTION REFRIGERATORS Filed May 51, 1930 I5 Sheets-Sheet 1 /& 6

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dttouwg S July 11, 1933. 1.. s. CHADWICIVKEI AL GAS BURNING APPLIANCEFOR ABSORPTION REFRIGERATORS Fi led May 31, 1930 5 Sheets-Sheet 2 Jul11, 1933. s. CHADWICK ET AL 1,917,751

GAS BURNING APPLIANCE FOR ABSORPTION REFRIGERATORS Filed May 31, 1930 5Sheets-Sheet 3 July 11, 1933. L. S.CHADWICK Er AL 1,917,751

GAS BURNING APPLIANCE FOR ABSORPTION REFRIGERATORS Filed May 31, 1930 5Sheets-Sheet 4 Z UP July 11, 1933. L. s. CHADWICK El AL 1,917,751

GAS BURNING APPLIANCE FOR ABSORPTION REFRIGERATORS Filed May 31, 1930 5Sheets-Sheet 5 oocoooooooooooooo'oo Q 3mm; #3 93m W M 2 35% w uw 96WAWIMQM w @atented July 11, 1 97331 UNITED STATES PATENT OFF-ICE LEE S.CHADWICK, OF

SHAKER HEIGHTS VILLAGE, MARC RESEK, OF CLEVELAND HEIGHTS; AND WILBUB G.MIDNIGHT, OF CLEVELAND, OHIO, ASSIGNORS TO PER- FECTION STOVE COMPANY,OF CLEVELAND, OHIO,

A CORPORATION OF OHIO GAS BURNING APPLIANCE FOR ABSORPTION BEFRIGERATORSApplication filed May 31, 1930. Serial No. 457,881.

This invention relates to a gas burning appliance for use especiallywith intermittent absorption refrigerators, more particularly with a asburner attachment for converting oil-fired refrigeration apparatus, ofthe t pe shown in the copending application of gee S. Chadwick and MarcResek, two of the present applicants, filed June 26, 1929, Serial No. 373,740, into gasfired apparatus.

Among the more general objects of the invention are those of providing arelatively sim 1e gas burning appliance that is especial y convenient ofuse; that is economical of manufacture; that incorporates reliableautomatic shut-off mechanism, and wherein said mechanism is readilyadjustable to take care of various temperature conditions.

Other objects of the invention are to provide a gas burning attachmentthat map be easily and quickly applied to existing re rigerators as asubstitute for the oil burning apparatus wherewith they were originallyequipped, and which has provisions or adjusting it to the differentdimensions of various models.

It will be seen from the above that, by reason of our invention, anowner of an oilfired refrigerator may readily and at nominal expenseconvert the same into one in which gas may be used if and when thelatterfuel becomes available to him.

Objects and advantages additional to those above set forth will becomeapparent as we proceed tovdescribe the invention by reference to theaccompanying drawings wherein embodiments of the same are illustrated.In the drawings,

Fig. 1 is a fragmentary sectional side elevation of a. refrigerator towhich the gas burning appliance of our invention is applied;

Fig. 2 isa similar front elevation on a scale somewhat enlarged overthat of Fig. 1;

Fig. 3 is a section substantially on the line 33 of Fig. 2;

Fig. 4 is a plan view of the casing that con- I stitutes the base of theappliance with the cover removed to disclose the operating parts housedtherein;

and it has to do- Fig. 5 is a section on the line 5-5 of Fig. 4;

Fig. 6 is a transverse section through the base on the line 66 of Fig.4; and

Fig. 7 is a View, similar to Fig. 3, showing a modification. I

The refrigerator (as may be seen more fully by reference to the abovementioned application Serial No. 873,740) includes a base 1, in thenature of a horizontal frame, that is supported a suitable distanceabove the fioor, by legs 2. A cabinet 3, that encloses the refrigerationcompartment, is mounted upon the base and is spaced from the left handside thereof, as viewed from the front in Fig. 2, and above theunoccupied portion of the base is a combustion chamber 5 that is closedon one side by the adjacent wall of the cabinet 3, and the remainder ofthe way around by a side wall 6, a rear wall 7 and a front wall 8, thelatter having a door through which access is had to said cham- Supportedwithin the combustion chamber a suitable distance above the base 1 isthe generator 10 of the apparatus. This generator consists of acylindrical vessel surrounded by heat abstracting fins 11.

As will be readily understood by those familiar with intermittentabsorption refrigerators, the generator forms a part of anintercommunicating closed system, including an evaporator and acondenser (not shown) and permanently containing a refrigerant, such asammonia, and an absorbent therefor, such as water, in properproportions, and at given intervals the mixture is heated in thegenerator for the purpose of driving off the refrigerant vapors therebyto initiate a cycle of operation. In the type of refrigerator hereinshown a combustion device is adapted to be sustained below the generatorby a support 12 which, in the present instance, consists of opposedguides 13 in the form of inwardly facing channel members that aresupported at their opposite ends by brackets 14. The respective bracketsare secured to the base 1.

The gas burning appliance (provided by front and rear sides of the oilburning outfit wherewith the refrigerator was originally equipped andwhich outfit was removably supported by the guides 13) consists,generally, of a base 20, and a gas burnor 21 that is supported, througha bracket 22 from the base 1, in operative relation to the generator 10,the base 20 resting on the front ends of the guides 13 of the burnersupport. A cross member 23 is secured to the bottom of the base 20 nearits rear side, and the ends of said member are formed for engagementbeneath the top flanges of the channel guides 13. The bracket 22 isprovided with two sets of slots, those of one set being designated 25,and those of the other 26, and screws 27 are adapted to be engagedthrough either the slots 25 or 26 and threaded into bosses 28 of thecasting which forms the burner 21. The two of slots provide anadjustment for adapting the appliance to different models of therefrigerator in which the generators are spaced different distancesabove the burner support 12.

The base 20 consists of a casing that encloses a valve for controllingthe supply oil gas to the burner, and also mechanism for actuating thevalve, including a pressure iluid device that is part of a thermostaticmechanism involving an arcuate bulb 30 designed for engagement with theunder side of the generator 10 directly above the base 20, the sameoccupying the space between the lower sides of adjacent fins 11. A cover31 is secured, as by screws 32, to the casing forming the base 20. Thebracket 22 is suitably fastened to the cover 31 and forwardly of theupright portion of the bracket to which the burner is attached, is ascrew 33 that is secured to and rises from the cover. A wing nut 34operates on the screw and supports a sleeve 35 which bears at its upperend against the central portion of the bulb 30. By turning the nut 34upwardly the sleeve is elevated to press said bulb 30 firmly against theenerator 10 and the screw 33 is depresse to force the base 20 tightlyagainst the burner support 12. Thus the appliance is clamped securely inplace, and intimate contact is assured between the bulb 30 and thegenerator wall so as to promote heat interchange between the two. Whenthe parts are in clamping condition, the upper end of the sleeve 35 maybear against the adjacent fins 11.

A shield 36, in the nature of a flat plate, formed at its upper edge tofit the curvature of the generator, is supported by the bracket 22between the bulb 30 and the burner 31. The shield includes an extension37 which bears against the rear side of the bracket 22 and has avertical slot 38 through which screws or bolts 39 are engaged, saidscrews or bolts occupyin a ertures in the bracket. The slot 38 provi esor ad'usting the shield 36 for the same purpose that the burner is madevertically adjustable, as hereinbefore explained. This shield protectsthe bulb 30 from the direct heat of the burner flame and makes itdependent, for its actuating heat, upon the generator.

Referring now to Figs. 5 and 6, a gas valve 40 is mounted within thebase, the same being shown as held in. place by a screw 41 that extendsthrough an opening in the bottom wall, and by screws 4-2, that extendthrough the rear wall, of the casing that constitutes the base. lhisvalve includes a member 14-, formed by the tapered end of a stem 45,which is arranged to engage a seat 46 that surrounds an inlet port 47.This port communicates with supply pipe 48 through which gas isdelivered to the appliance from any suitable source, as from a main, orfrom interchangeable portable tanks that are being used in increasingnumbers in rural communities for delivering gas to users. A spring 49surrounds a part of the valve stem and is compressed between the wall ofthe valve casing through which the stern projects and an abutment 50that is secured to the stem near its tapered end. The spring tends toseat the valve member, and the latter is adapted to be retracted inopposition to action of the spring by an operating handle 51 to whichthe valve stem is connected through a link 52. This link is shown asconstruct/ed of a rod of suitable length which has its front and rearends turned downwardly and engaged, respectively, through an aperture inthe operating handle 51 and a hole in the forward end of the stem 45.The operating handle is pivotally supported by a pin 53 that is shown asextended through aligned apertures in the bottom wall of the base and ina horizontal portion of a bracket 54:. This bracket is notched at 55,and when the operating handle is thrown to the left, as the parts areviewed from the front, until the forward downturned end of the link 52engages the right hand wall of the notch 55, the point of connectionbetween the link and the operating handle is beyond dead center so tospeak, which means that it has been moved through and beyond the directline of movement of the valve, which line is shown as coincident withthe pivotal axis of the operating handle. By reason of this arrangement,the valve is held retracted against the action of the spring 49 when theoperating handle is in the position shown in the drawings.

The thermostatic mechanism, whose purpose it is to automatically releasethe valve so as to allow the spring 49 to close it when the temperatureof the generator rises to a predetermined degree, will now be described.56 is a lever which is referably made of sheet metal in the form 0 achannel. At its rear end the side flanges of the channel are extended be0nd the web thereof, as clearly shown in hig. 4, and the extendedportions of said flanges are notched at and projected through aperturesin the rear wall of the base, the notches 6O embracing the adjacentportions of said wall to define a pivotal axis on which the leverswings. The opposite end of the lever has a lateral extension 61 thatoverlies and bears upon the enlarged inner end of the operating handle51 in a position to strike the forward end of the link 52. A tension.spring 62 has one of its ends connected to the lever 56 and its oppositeend attached to an arm 63, and said spring tends to withdraw the lateralextension 61 of the lever from the link 52. The arm 63has its rear endprojected through an aperture 65 that is formed in one branch of anangle member 66 that is suitably secured within the rear corner of thebase opposite the valve 40. The arm has a notch 68 that is engaged witha side wall of the aperture 65 to provide a fulcrum for the arm. Theforward ends of the arm 63 and the operating handle 51 extend throughrespective slots 69 and 7 Othat are formed in the front wall of thebase, and the slot 70 is of a shape to provide a series of stops,designated 71, 72 and 73, with any one of which the arm may be engaged.Thus the tension of the spring 62 maybe varied, and a further adjustmentmay be obtained by hooking the forward end of the spring in any one of aplurality of openings 74 in the arm 63. Suitable indicating marks may beassociated with the slots 69 and 70, as shown in Fig. 2, to facilitatethe adjustment of the arm 63 for changing the tension of the spring 62,and to show when the valve 40 is open and closed.

Supported by the angle member 66, be a pressure fluid tween it and thelever 56, is

device 75. As best shown in Fig. 6, this device consists of a bellows 76whose opzposite ends are secured and sealed to heads 7 and 78, theformer head including a threaded stud 79 that is projected through ahole in the angle member 66 and has applied to it therebeyond a clampingnut 80. The head 7 8 has a recessed extension 81 that is piloted upon apin 82 on the lever 56. A spacing sleeve 83 extends from the head 77forwardly and is adapted to be engaged by the head 78 when the bellows76 is in contracted condition. The sleeve has an opening 84 for insuringfree communication at all times between its interior and thespaceexterior of itthat is enclosed by the bellows 76. A tube 85 connects thepressure fluid device 7 5 with the previously metioned bulb 30, so thatthe two are in direct communication at all times, and a suitable fluidis contained within the enclosure of this assembly. Water is foundsuitable fonthe purpose, and in Fig. 2 the level thereof in the bulb 30is indicated at a.

operates is determined by f The cover 31 is notched at 86, and thesleeve 35 is notched at 87 to accommodate the tube 85. The tube is longenough and flexible enough to yield to the vertical adjustments of theappliance that are necessary in order to adapt the appliance todifferent models of the refrigerator.

In order to revent deformationof the cover 31 of the ase, which mightotherwise result from the pressure exerted downwardly thereon by thescrew 33, an'abuiment 88 is interposed between the cover and the bottomwall of the base, the same being shown as an angular post that issuitably attached to the bottom wall.

To avoid the use of a stufiing box for preventing leakage of gas aboutthe valve stem 45, and which would have obvious disadvantages in thispartlcular instance where ab-- solute freedom of movement of the valvestem is essential, we employ a metallic bellows 90 whose opposite endsare sealed, respectively, to the forward end of the valve casing and toa head 91 that is brazed or otherwise secured to the valve stem 45. Atubular fitting 93 connects the valve 10 with the mixer of the burner21.

In the use of refrigerators of the class herei in refered to, the burneris lit at reasonably regular intervals, for example, at about the sametime every morning, and it is allowed to burn long enough to distillover inio the evaporator of the apparatus a full charge of anhydrousrefrigerant. In the case of liquid fuel burners, the length of time thecombustion device operates is fixed by placing only a limited quantityof oil in the font or reservoir of the burner. The burner goes out whenthe oil supply is exhausted. In the present case,

the temperature of the generator. Assuming that the burner has been litin order to initiate a cycle of operation of the apparatus, the burnerfunctions until a given degree of temperature has been reached in thegenerator that is sutliciently high to insure the required amount ofrefrigerant being distilled over into the evaporator. When such atemperature has been reached, the fluid in the bulb 30 expands, creatingpressure that is transmitted to, and results in the elongation of, thebellows 76. This action of the bellows swings the lever 56 so as tothrow the forward end of the link 52 over center so to speak, or, inother words, to move it through the line of movement of the valve 44,thereby releasing the valve and permitting the spring 49 to snap itagainst the seat 46', the operating handle 51 swinging in the meantimeto oil position.

When it is time again to light the burner,

which 'is at the conclusion of the present cycle of operation of theapparatus, the door 9 is opened and the operating handle 51 is thelength of time the burner.

swung to on position, thereby to open the valve 40 and retain it open,when the burner may be lit in the ordinary manner.

As previously stated the shield 36 protects the bulb 30 from the radiantand more direct heat of the burner flame. It has also been explained howthe shield and the burner can be adjusted vertically to adapt theappliance to different models of refrigerators, the slot 38 in theextension 37 of the shield, and the two sets of slots 25 and 26 in thebracket 22, roviding for such adjustments. The nut 34 1s, of course,adjustable up and down on the screw 33 so that the base 1 and bulb 30may be adjusted toward and from each other, for the same purpose, andthe tube 85 is of sufficient length and flexibility to permit of suchadjustments.

Inasmuch as different springs vary in tension to a greater or lessdegree, provision is made to compensate for such variations with respectto spring 62 by making a series of holes 74 in the arm (33. The forwardend of the spring is hooked into such of these holes as will create thedesired tension in the particular spring used. Under normal conditions,the arm 63 is engaged with the center stop 72 that is formed at thebottom of the slot in the front wall of the base through which the armprojects. If, in the operation of the apparatus, it is found that therefrigeration space does not become cold enough, the arm 63 may beengaged with stop 71 so as to increase the tension of the spring andthus cause the burner to operate for a longer period of time, thereby todistill over into the evaporator a greater quantit of refrigerant withthe result that the re rigeration compartment will become colder beforethe next heating period is reached. It follows from this that if thetension of the spring 62 is decreased by engaging the arm 63 with thestop 73, the burner 40 will be shutofi after a shorter period of timeand there will be less refrigerant to effect the chilling of therefrigeration com-.

partment.

In the modification illustrated in Fig. 7, we have provided means forpositively closing the as line in case the gas pressure drops be ow apredetermined value or the flow ceases altogether. This is for the ob-.

vious purpose of safeguarding against the serious consequences thatwould result from a resumption of gas pressure while the valve of theappliance is open. Such a condition,

might be met in connection with the previously mentioned systems inwhich portable tanks are used for supplyingthe gas. If the burner werein operation at the time a tank of gas became exhausted, for example,and a new tank were then attached to the line before closing the valveof the appliance, there would be an escape of gas at the burner unlessthe burner were immediately lighted.

of the valve 108 t a valve 108 cooperates. This valve is carried by adiaphragm 110 Whose peripheral portion is clamped between opposed partsof the casing 101. A spring 111 tends to close the valve, and the valveis adapted to be retracted against the tension of said spring by a rod112 which terminates at its forward end in a handle 113 that is disposedjust inside the door 9 above the base of the appliance;

In order to light the burner, it is first necessary to open the valve 40by means of the handle 51 and then withdraw the valve 108 from the seat107 by ulling on the rod 112. The burner may now be lit, and thepressure of gas against thediaphragm 110, which is considerably greaterthan the force of the spring 111, holds the valve 108 off its seat; butin case of a failure of the gas supply, the valve is seated by thespring 110.

Now, in the event the gas pressure returns to normal, the valve 108 willnot open because of the fact that the gas cannot gain access to the diahragm 110, and the area hat is ex osed to the gas in the chamber 102 isso smalFthat the as pressure applied thereto is'quite insu cient toovercome the s ring 111. The presence of the valve 100 a so serves as acheck against any leakagewhich might occur in the valve l-Iaving thusdescribed our invention, what we claim is the refrigerator fork shiftingsaid means in said opposite direction.

2. A gas burning appliance for absorption refrigerators comprising aburner, a valve biased toward closed position for controlling thedelivery of gas to the burner, means movable through an arcuate coursein part transversely of the line-of movement of the'valve for openingthe valve, said means when moved through and beyond said line in onedirection serving to hold the valve open, and thermostatic mechanismarranged to be subjected to the temperature of the generator of therefrigerator for moving said means in the opposite direction throughsaid line.

3. A gas burning appliance for absorption refrigerators comprising aburner, a valve biased toward closed position for controlling thedelivery of gas to the burner, manually operated means movable throughan arcuate course in part transversely of the" line of movement of thevalve and connected to said valve for opening the same, said means whenmoved through and beyond said line in one direction serving to hold thevalve open, and thermostatic mechanism arranged to be subjected to the.temperature of the generator of the refrigerator for movingthe oppositedirection through said line.

4. A gas burning appliance for absorption refrigerators comprising aburner, a valve biased toward closed position for controlling thedelivery of gas to the burner, means movable through an arcuate coursein part transversely of the line of movement of the valve and connectedto said valve, a stop engaged by said means yond said line in onedirection, said means when engaging the stop serving to hold the valveopen, and thermostatic mechanism arranged to be subjected to thetemperature of the generator of the refrigerator for dislodging saidmeans from the stop and moving it in the opposite direction through saidline.

5. A gas burning appliance for absorption refrigerators comprising aburner, a valve biased toward closed position for controlling thedelivery of gas to the burner, a member pivotally supportedsubstantially on the line of movement of the valve, a link connected atone end to the valve and at the other to said member beyond the latterspivotal sup port so that the latter end of the link passes through andbeyond the line of movement of the valve when the member is swung in onedirection, and thermostatic mechanism arranged to be subjected to thetemperature of the generator of the refrigerator for moving the lastmentioned end of the link in the opposite direction through said line.

6. A gas burning appliance for absorption refrigerators comprising aburner, a valve biased toward closed position for controlling thedelivery of gas to the burner, a pivotally supported valve operatingmember, a link connecting the valve and said member, the

point of connection between the link and member passing through .theline of movement of the valve on the side of the pivotal axis of themember remote from the valve, a stop for holding the member againstfurther movement when said point has passed a short distance beyond saidline in one direction, and

said means in when moved through and bethermostatic mechanism arrangedto be subjected to the temperature of the generator of the refrigeratorfor moving the member and thereby shifting said point in the oppositedirection beyond said line.

7. A gas burner appliance for absorption refrigerators comprising aburner, a valve for controlling the delivery of gas to the burner, saidvalve being biased toward closed position, releasable means for holdingthe valve open, a member movable to release said means, thermostaticmechanism arranged to be subjected to the temperature of the generatorof the refrigerator for moving said member, a pivoted lever, a springinterposed between the lever and member for opposing the movement of thelatter by said thermostatic mechanism, and a plurality of stopswherewith said lever is adapted to be engaged for varying the tension ofsaid spring.

8. For use with absorption refrigerators incorporating a generator and aburner support situated below and in fixed relation to the generator, agas burning appliance comprising a base for application to said support,a burner sustained thereby in operative relation to the generator,mechanism controlling the supply of gas to the burner, said mechanismincluding a thermostatic element for engagement with the underside ofthe generator, and means interposed between the base and said elementfor holding the element firmly against the generator,

9. For use with absorption refrigerators incorporating a generator and aburner support situated below and in fixed relation to the enerator, agas burning appliance comprising a base for application to said support,a burner sustained thereby in operative relation to the generator, andmeans interposed between the base and generator for holding the basefirmly upon the burner support.

10. For use with absorption refrigerators incorporating a generator anda burner support situated below and in fixed relation to the generator,agas burning appliance comprising a base for application to saidsupport, a burner sustained thereby in operative relation to thegenerator, and extensible means interposed between the base and thegenerator for depressing the base and thus holding it firmly upon thesupport.

11. For use with absorption refrigerators incorporating a generator anda burner support situated below and in fixed relation to the generator,a gas burning appliance comprising a base for application to the burnersupport, a gas burner sustained thereby in operative relation to thegenerator, a valve for controlling the supply of gas to the burner,valve actuating mechanism, thermostatic means for controlling saidmechanism, said thermostatic means including a member for application tothe underside of the generator above the base of the appliance, andextensible means interposed between said member and the base for urgingthe member upwardly against the generator and the base downwardlyagainst the burner support.

12. For use with absorption refrigerators incorporatinga generator and aburner support situated below and in fixed relation to the generator, agas burning appliance comprising a base for application to the burnersupport, a gas burner sustained thereby in operative relation to thegenerator, a valve carried by the base for controlling the supply of gasto the burner, valve actuating mechanism, thermostatic means forcontrolling said mechanism, said thermostatic means including a memberfor application to the underside of the generator above the base of theappliance, and an extensible device interposed between said member andthe base and consisting of a screw and a sleeve surrounding the same,and a nut operable upon said screw and wherewith one end of the sleeveengages.

13. For use with absorption refrigerators incorporating a generator anda burner support situated below and in fixed relation to the generator,a gas burning appliance comprising a base for application to the burnersupport, a gas burner sustained thereby in operative relation to thegenerator, a valve for controlling the supply of gas to the burner,valve actuatin mechanism, thermostatic means for contro ling saidmechanism, said means includin a thermostatic element for application totile underside of the enerator above the base of the appliance, an ashield supported from the base in juxtaposition to the generator betweensaid element and the burner. r

14. For use with absorption refrigerators incorporating a generator anda burner support situated below and in fixed relation to the generator,:1 gas burning appliance comprising a base for application to the burnersupport, a gas burner sustained thereby in operative relation to thegenerator, a valve for controlling the supply of gas to the burner,valve actuatin mechanism, thermostatic means for contro ling saidmechanism, said means includin a thermostatic element for application tot e underside of the enerator a mm the base of the appliance, an ashield supported from the base in juxtaposition to the generator betweensaid element and the bglrner, said shield being vertically adjusta e.

15. For use with absorption refrigerators incorporatin a enerator and aburner support situate be ow and in fixed relation to the generator, agas burning appliance comprising a base for application to the burnersupport, a gas burner sustained thereby in operative relation to thegenerator, a valve for controlling the supply of gas to the bumer, valveactuating mechanism-thermost tic means for controlling said mechanism,said means including a thermostatic element for application to theunderside of the generator above the base of the appliance, the elementconforming substantially to the contour of the enerator, a screw risinfrom the base beneath said element, a nut adjustable along said screw,and a sleeve bearing upon said nut and having its upper end engaged withsaid element.

16. For use with. absorption refrigerators incorporating a generator anda burner support therebelow, a as burning appliance comprising abase rorapplication to the burner support, a bracket risin from the base, aburner adapted to be sustained at different elevations by said bracket,a valve "for controlling the supply of gas to the burner, valveactuating means, thermostatic mechanism for governing the action of saidmeans, said mechanism including a member for engagement with theunderside of the generator above the base, extensible means interposedbetween said member and the base for urging the former upwardly incontact with the generator and the latter downwardly upon the burner suport, and a shield supported by the brac et between the burner and saidmember, the said shield being vertically adjustable with respect to thebracket.

17. For usewith absorption refrigerators incorporating a generator and aburner support therebelow, a gas burning appliance consisting of acasing constituting a base for application to the burner support, abracket rising from the casing, a burner sustained by the bracket inoperative relation to the generator, a valve within the casing forcontrolling the supply of gas to the burner, valve actuating means withmthe casing having a handle for manual operation accessible from outsidethe casing, thermostatic mechanism for controlling the operation of thevalve actuating means, said mechanism includin a member for applicationto the bottom 0 the generator above the base, thrust means interposedbetween said member and the base, and a shield supported by the bracketin juxtaposition to the generator between the burner and the aforesaidmember of the thermostatic mechanism.

18. For use with absorption refrigerators incor orating a generator anda burner support t erebelow, a gas burning ap liance consistin of acasing constituting a see for applicatlon to the burner support, abracket rising from the casin a burner sustained by the bracket inoperative relation to the generator, a valve within the casin for comtrolling the supply of gas to the burner, valve actuating means withinthe casing having a handle for manual 0 eration accessible from outsidethe casing t ermostatic mechanism for controlling t e' operation of thevalve actuating means, a spring within the casing opposing the action ofthe thermotatic mechanism, means for adjusting the tension of the springaccessible from outside the casing, said thermostatic mechanism1ncluding a member for application to the bottom of the generator abovethe base, thrust means interposed between said member and the base, anda shield supported by the bracket in juxtaposition to the generatorbetween the burner and the aforesaid member of the thermostaticmechanism.

19. In combination with the generator of an absorption refrigerator,said generator being provided with spaced heat abstracting fins, meansfor heating the generator, mechanism for controlling the action of saidheating means involving a thermostatic element that is adapted to besubjected to the heat of the. generator, said element being held inintimate heat-exchanging relation to the generator between adjacent finsthereof.

20. In combination with a cylindrical generator of an absorptionrefrigerator, means for heating the same, and mechanism for controllingthe action of said heating means including an elongated thermostaticelement of substantially the same cross-sectional area throughout itslength, said element being adapted to be applied to the exterior of thegenerator and curved bodily from end to end to approximately fit thetransverse curvature thereof.

21. A gas burning appliance for absorption refrigerators comprising aburner, a

' valve for controlling the delivery of gas to the burner, and a secondvalve governing the flow of gas between the first valve and the burner,means tending to close the second valve, manually operated means foropening said second valve, and means operated by the gas pressure forretaining the secondmentioned valve open when it has been manuallyopened but-which is incapable of opening the valve when the latter isclosed.

22. A gas burning appliance for absorption refrigerators comprising aburner for heating the generator, a valve biased toward closed positionfor controlling the delivery of gas to the burner, means for holding thevalve open, thermostatic mechanism arranged to be subjected to thetemperature of the generator for rendering said holding meansineffective, a second, self-closing valve which operates in conjunctionwith the first mentioned valve for controlling the flow'of gas to theburner, manually operated means for opening said valve, and meansoperated by the gas pressure for retaining the second mentioned valveopen but incapable of opening the same.

23. A. gas burning appliance for absorption refrigerators comprising aburner, a conduit through which gas is supplied to the burner, twovalves arranged one ahead of the other in said conduit for controllingthe supply of gas to the burner, both of said valves being biased towardclosed position, individual means for manually opening each of saidvalves, thermostatic means subjected to the temperature of the generatorof the apparatus for effecting the closing of one of said valves, theother of said valves being held open by gas pressure and closing in casethe gas pressure falls below a predetermined value, the gas pressurebeing incapable of opemng said valve.

In testimony whereof, we hereunto alfix our signatures.

LEE S; CHADWICK. MARC RESEK. WILBIJR G. MIDNIGHT.

